Heat exchanger



1952 A. J. J. LAMBEEK 2,616,672

HEAT EXCHANGER Filed July '15, 1950 a a I y 7 v INVENTOR. ADRIAAN JANJURRIAAN LAMBEE K AGE Patented Nov. 4, 1952 2,616,672 'HEAT EXCHANGERAdriaan J an Jurriaan Lambeek, Dordrecht, Netherlands, assignor toHartford National Bank and Trust Company, Hartford, Conn., as trusteeApplication July 15, 1950, Serial No. 174,025 In the Netherlands August17, 1949 This invention relates to heat exchangers having a cylindricalwall through which the heat exchange takes place. With heat exchangersof this type a medium passes over the exterior of the cylindrical walland is in heat-exchanging contact, through the wall, with another mediumpassing over the interior of the cylindrical wall. As a rule, thewall-of such a heat exchanger is furnished, bothexternally andinternally, with projecting parts e. g. ribs. It'is-also known toprovide a strip of material, for example, zig-zag in section, at theinner side of the wall, thus forming channels for the working medium andconsiderably increasing the heat exchanging surface of the wall.However, these constructions have a limitation in that the provision ofuniform folds in the material is comparatively difiicult. In anotherknown construction, the ribs and the wall are formed integrally bycasting. This construction also has the disadvantage that a preciseconstruction entails difliculties. The aforesaid known constructions areoften used in hotgas reciprocating apparatus, which term is to beunderstood to include hot-gas reciprocating engines and refrigeratingapparatus operating according to the reversed hot-gas reciprocatingengine principle.

The present invention has for its object to provide a heat exchanger ofsimple construction in which the channels for the working medium are ofa correct size.

According to the invention, a heat exchanger having a cylindrical wallthrough which heat exchange is to take place is characterized in thatsegments, jointly constituting a cylinder, are provided at the interiorof the wall and throughout its periphery, at least part of he saidsegments being provided with channels for passage of a medium to be inheat exchanging contact with the wall. The aforesaid segments arecheaply obtainable, for instance, by extrusion, drawing or milling.

In order to ensure a satisfactory heat transfer through the wall to thesegments, the interior of the cylindrical wall may be subject to surface1 pressure exerted by the cylinder consisting of segments. Thus, theouter diameter of the cylinder consisting of segments may exceed theinside diameter of the cylindrical wall. Due to this the material of thesegments becomes deformed on insertion, for example, with the use ofthermal shrinking into the cylindrical wall, thus ensuring an intimatecontact between the segments and the cylindrical wall.

The segments may be secured to the wall by r 3 Claims. (Cl. 257261)soldering, which may be efiected without the use of special tools. Thesoldered joint is corrosion proof, since only a small surface area ofthe joint is exposed to the air. 7

The channels provided in the segments may extend according to ageneratrix of this segment and terminate at a cylindrical surfacethereof.

For'the manufacture of the segments, it is advantageous if the sidewalls of the channels extend parallel to one another in such segment.

In order that the invention may be more clearly understood and readilycarried into effect, it will now be described in greater detail withreference to the accompanying drawing, given by way of example, whichrepresents diagrammatically a hot-gas reciprocating engine comprisingone embodiment of a heat exchanger according to the invention.

Fig. 1 is a longitudinal section of part of the engine and Fig. 2 is asection taken on the line II-II of Fig. 1.

The hot-gas reciprocating engine comprises a displacer l and piston 2reciprocating with a constant phase diiference and connected to adriving mechanism (not represented). The space above the displacer isthe hot space 3, whereas the space between the displacer and the pistonis the cold space 4. The spaces 3 and 4 are interconnected through acooler 5, a regenerator B, and a heater 1. The heater has a cylindricalwall 8 over the exterior of which the combustion gases pass. These gasesare supplied from a burner 9 to the heater 1 and escape therefromthrough a channel l0. As is shown in Fig. 2, the cylinder 8 is providedwith external ribs I and internal segments [2 are provided havingchannels I3 which extend according to a generatrix of the segment andterminate at the cylindrical inner surface of this segment. The sidewalls of each channel extend parallel to one another. For convenience ofmanufacture, it may be advantageous if the side walls of all thechannels in each segment are parallel to one another. In order toseparate the hot space from the space within the heater, 9. cylinder [4is provided within the segments.

It will be obvious that the use of the heat exchanger according to theinvention is not limited to hot-gas reciprocating apparatus, but mayalso be used in other apparatus.

What I claim is:

1. A heat exchanger having a cylindrical wall through which heatexchange is to take place, a plurality of segments provided on the innerperiphery of said wall and jointly constituting a cylinder thereon, partof each segment being formed with channels for the passage of a mediumto be in heat exchange contact with the wall, each of said channelsextends according to the generatrix of the segment and each channelterminates at a cylindrical surface of the segment, and the side wallsof each channel extending substantially parallel to each other and eachchannel being of substantially the same dimensions and spaced away fromsaid wall.

2. A heat exchanger having a cylindrical wall through which heatexchange is to take place, a plurality of segments secured to the innerperiphery of said wall by soldering and jointly constituting a cylinderthereon, part of each segment being formed with channels for the passageof a medium to be in heat exchange contact with the wall, each of saidchannels extends according to the generatrix of the segment and eachchannel terminates at a cylindrical surface of the segment, and the sidewalls of each channel extending substantially parallel to each other andeach channel being of substantially the same dimen-- sions and spacedaway from said wall.

, 3. A heat exchanger having a cylindrical wall through which heatexchange is to take place; said wall being provided with a plurality ofexternal ribs on the outer periphery of said wall. a plurality ofsegments provided on the inner periphery of said wall and jointlyconstituting a cylinder thereon, the outer diameter of said cylinderexceeding the inner diameter of said cylindrical wall so that thecylindrical wall is subject to surface pressure by said cylinder whenmounted on said inner periphery, part of each segment being formed withchannels for the passage of a medium to be in heat exchange contact withthe wall, each of said channels extends according to the generatrix ofthe segment and each channel terminates at a cylindrical surface of thesegment, and the side walls of each channel extending substantiallyparallel to each other and each channel being of substantially the samedimensions and spaced away from said wall.

ADRIAAN JAN J URRIAAN LAMBEEK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date r 1,460,677 Lundgaard July 3,1923 1,511,023 Brown Oct. 7, 1924 1,730,580 Lundgaard Oct. 8, 19291,849,086 Hehr Mar. 15, 1932 2,012,739 Brown Aug. 27, 1935 2,114,238Rabatel Apr. 12, 1938 2,406,552 Lucke Aug. 27, 1946 2,567,637 De Brey etal Sept. 11, 1951

